Bartender-about-town Vincenzo Marianella is coming up with cocktails faster than he can name them.

Like "the apple one," on his first-run drinks menu at the Doheny, the downtown members-only cocktail lounge just days away from opening.

Marianella captured L.A. cocktail connoisseurs' attention at Providence in Hollywood, the Michelin-starred restaurant where until last month he held court over the elegant six-seat bar. Now he's head barman at the Doheny, and his apple cocktail is a heady, compelling mixture of rich Elijah Craig bourbon and fragrant St-Germain elderflower liqueur with fresh lime and organic apple juice, poured over crushed ice and garnished with sliced apples.

Then there's the as-yet-untitled, deliciously Italian-inflected drink of house-made limoncello with Campari and ginger beer that he created as a consultant for the newly expanded Osteria La Buca.

At a party for the Melrose Avenue restaurant's reopening, ladies are clamoring for his version of a Rossini -- muddled strawberries and Prosecco to which he adds a little Campari. A fresh-faced actor type emerges from the crowd and flags down Marianella: "Hey, what do you call that drink?" he asks, referring to a cucumber-apple-vodka number. "I have to have another one."

Marianella, a 36-year-old Italian expat and onetime semipro basketball player who rides a Suzuki dual-sport and is wont to wear Roberto Cavalli sunglasses, has become a torchbearer for the professional bartender in this city. "It used to be that everybody assumed you did something else too, that we're all actors, especially here in Los Angeles," he says. "But people are beginning to understand it's a profession, a real profession."

L.A.'s sipping scene already has caught on to fresh ingredients, classically rendered cocktails and baroque bartending standards, but few seem to have a sophisticated cocktail repertoire as deep and varied as Marianella's. The Doheny drinks menu eventually will list 75 cocktails, "maybe 100," Marianella says -- at a time when other notable mixed-drink hot spots have consciously put forth just a few proper concoctions at a time. Comme Ça's menu lists four cocktails; the new Father's Office is expected to offer the same number, not including a couple of "secret" ones.

An extensive drinks list is "a challenge; you have to move a lot of cocktails," says Marianella, who has a way with brown spirits (not one to shy away from using, say, Laphroaig or even a 55-year-old Macallan in a cocktail) but who lately has had a penchant for tequila, apples and St-Germain (though "not in one drink -- yet"). "I like the idea that someone can explore and find something they like and come back for it."

London calling

HIS first bartending job was at 19, at a cafe in his native province of Udine in northeastern Italy ("in the middle of nowhere"), pouring espresso, wine, grappa, amari (bitter Italian liqueurs). After he left basketball (he played for the team Andrea Costa Imola), he traveled and at first bartending was a way "to make a few dollars and meet a lot of girls." Stints at restaurants and bars in L.A., New York, and Sydney, Australia, eventually led to London in 2003, and that's where "I fell in love with the craft; I really understood and realized it was a career."

While working at a bar called Smollensky's, he immersed himself in the bar culture of what is arguably the best cocktail city in the world.

At the time, legendary barman Salvatore Calabrese, whom Marianella cites as one of his idols, was presiding over the Library Bar at the Lanesborough Hotel, making bespoke cocktails for the likes of Bill Gates and Naomi Campbell; chef-turned-bartender Robert Wattie was slinging drinks at the chic Lobby Bar; and cocktail guru Dick Bradsell was spearheading the bar at one white-hot spot after another -- the Atlantic Bar & Grill, Match, Six Degrees, the Player, the Lab and the Long Bar at the Sanderson Hotel.

"I'd work, make money for five or six days, then go out drinking," Marianella says, "and I'd steal techniques."

L.A. story

WHEN he moved back to Los Angeles, he eventually brought those techniques with him to Providence, where he came up with seasonal, spot-on cocktail menus. "I developed my skills at Providence, especially by creating cocktails for [chef Michael Cimarusti's] tasting menus," such as the Oriental Tangerine, which started on the tasting menu paired with a crab salad, but people kept ordering it at the bar -- a delicate cocktail of vodka, sake, lychee liqueur, fresh mint and Satsuma tangerines.

"It's not just about the measuring, the mixology," he says. "You really have to know how to balance -- so that no one flavor overwhelms another. And you have to be able to improvise for someone else's palate."

When a customer sidled up to the Providence bar and requested a Scotch cocktail, Marianella came up with the Smoke of Scotland -- Laphroaig, extra-dry vermouth, Cynar (the Italian artichoke-based liqueur) and St-Germain (he's been obsessed with the latter since long before it was "item of the week" on Style.com). "I'm really proud of that one," he says. "It came out perfect the first time." It's smoky, with floral and tropical fruit notes from the elderflower liqueur and added complexity from the vermouth and Cynar.

By last year, Marianella says, he was getting as many as three calls a week from those who wanted to hire him to create cocktails for their restaurants or parties. So he started his consulting business, MyMixology, and brought on partner Zahra Bates, who had worked at the Long Bar in London and has succeeded Marianella at the Providence bar.

Marianella strikes an imposing figure -- tall (he's been 6-foot-4 since he was 13) and with somewhat-Mephistophelean good looks (dark hair, trimmed mustache and goatee) -- but he's a warm and amiable barkeep, more precise than flamboyant. If you've ever sat in front of him at the bar at Providence, you may have noticed how he inspects each glass before he pours a drink or the way he might straighten your coaster.

He's a confident perfectionist -- but not overly confident; he tastes every drink he sends across the bar. (No, he's not drinking from your glass. He uses a straw and a little dexterity to siphon a sip before garnishing.)

"I can make mistakes," he explains. "But I can recognize immediately what it's missing. I can taste the whole profile of a drink in that twentieth of an ounce."

For the Doheny, Marianella has collected a library of about 200 spirits, which includes single-malt Scotches such as Langavulin 21-year-old and Bowmore 34-year-old, along with 55-year Macallan in a Lalique decanter; tequilas such as El Tesoro 70th Aniversario and Partida Elegante; Armagnacs such as Dartigalongue 1957 Bas Armagnac; a 1958 Coeur de Lion Calvados; and even aged Cachaças (the Brazilian sugar-cane-based spirit). He's still getting shipments in, and the initial menu will list 30 cocktails.

L.A.'s cocktail scene is catching up to the likes of New York, Marianella says. "There are, what, 10 to 15 great bars in Manhattan? We're getting there." Now, with Marianella's "London-style" cocktail menu (long on originals and classics both), L.A.'s bar scene is that much more cosmopolitan. On the horizon might be his own bar.

Marianella's menu is divided into original cocktails, Champagne cocktails, nonalcoholic cocktails (under Drivers Cocktails) and pre-Prohibition cocktails, as well as cocktails from around the globe -- from bartenders such as Francesco Lafranconi (another of Marianella's role models) in Vegas and Jacques Bezuidenhout in San Francisco.

"There are so many amazing bartenders all over the world," Marianella says. "And I wanted a menu that covers cocktail history and cocktail possibilities." Here's to possibilities.